The present invention relates to a method and apparatus for dispersing and transporting particulate matter.
U.S. Pat. No. 3,859,205 issued to Reba et. al. describes a system utilizing the Coanda effect to separate or disperse particulate matter such as polyethylene fibers or the like and transport the dispersed fibers to a predetermined location. The system of U.S. Pat. No. 3,859,205 has been utilized in conjunction with a forming bell to lay down a layer of fibers that have been dispersed and transported on to a moving wire to form a non-woven web. While the system of U.S. Pat. No. 3,859,205 has been satisfactory in most respects some operational difficulties have arisen under certain conditions.
One such difficulty was the asymmetrical loading of the apparatus at the outset, resulting in nonuniformity of the web being formed by the system. In co-pending U.S. application Ser. No. 12,178, filed Feb. 14, 1979, applicant discloses a system he has developed that results in the more uniform dispersement of the particulate matter prior to its introduction into the Coanda nozzle of the system. This is accomplished by providing an arrangement for placing the particulate matter in a fluidized state prior to such introduction.
Another problem that has arisen in the use of the system of U.S. Pat. No. 3,859,205 has been a diminishing rate of performance under high load volume conditions. Specifically, the arrangement of U.S. Pat. No. 3,859,205 subjects fiber clumps to severe shredding or dispersing forces as they enter and pass through a high energy air curtain. This effect, however, diminishes as the loading rate of clumps increases. A clump travelling in the wake of the preceding one can catch up, creating either a larger clump with sufficient inertia to go through the curtain or it escapes through a "hole" in a curtain formed by the leading clump. In other words, at high fiber loading rates the material does not have sufficient time to efficiently absorb energy supplied by the curtain.
It is an object of the present invention to provide a solution to the aforesaid problem and provide an improved apparatus and method for dispersing and transporting particulate matter resulting in the more efficient dispersion of particulate matter such as synthetic fibers, wood fibers, etc.